Abstract: Investigated the effects of prosocial and aggressive videogames on prosocial behavior in 80 3rd- and 4th-graders and 80 7th- and 8th-graders. Ss played either type of game singly or cooperatively with another child. A 3-way analysis of variance indicated that older Ss donated significantly more than younger Ss following the games. Ss who played aggressive videogames donated significantly less than those who played prosocial games by themselves. Results indicate that, while playing the prosocial videogame did not increase prosocial responding, playing the aggressive videogame tended to suppress this behavior. It is concluded that brief exposure to the games and the themes of the games may have contributed to the failure of the prosocial game to accelerate prosocial responding. (PsycINFO Database Record (c) 2004 APA, all rights reserved)